Environmental Protection Agency (EPA) Administrator Lisa Jackson announced Monday that "after a thorough examination of the scientific evidence and careful consideration of public comments," the agency has deemed greenhouse gases (GHGs) threaten the public health and welfare of the American people. Furthermore, the EPA specified that "GHG emissions from on-road vehicles contribute to that threat."

These findings, according to a transcript from Jackson’s speech on the matter, "provide the legal foundation for finalizing the recently proposed clean cars program. That program was developed in collaboration with the American auto industry and other stakeholders, and contains the nation’s first ever limits on greenhouse gas emissions from American vehicles.

And starting next spring, large emitting facilities will be required to incorporate the best available methods for controlling greenhouse gas emissions when they plan to construct or expand."

From a White House-issued press release on the ruling:

"EPA’s endangerment finding covers emissions of six key greenhouse gases — carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride — that have been the subject of scrutiny and intense analysis for decades by scientists in the United States and around the world.

Scientific consensus shows that as a result of human activities, GHG concentrations in the atmosphere are at record high levels and data shows that the Earth has been warming over the past 100 years, with the steepest increase in warming in recent decades. The evidence of human-induced climate change goes beyond observed increases in average surface temperatures; it includes melting ice in the Arctic, melting glaciers around the world, increasing ocean temperatures, rising sea levels, acidification of the oceans due to excess carbon dioxide, changing precipitation patterns, and changing patterns of ecosystems and wildlife.

President Obama and Administrator Jackson have publicly stated that they support a legislative solution to the problem of climate change and Congress" efforts to pass comprehensive climate legislation. However, climate change is threatening public health and welfare, and it is critical that EPA fulfill its obligation to respond to the 2007 U.S. Supreme Court ruling that determined that greenhouse gases fit within the Clean Air Act definition of air pollutants.

EPA issued the proposed findings in April 2009 and held a 60-day public comment period. The agency received more than 380,000 comments, which were carefully reviewed and considered during the development of the final findings."